The problems of transporting vehicles fall into two main categories. First, the vehicles must be packed in such a spatial configuration that they occupy the least possible volume, being both close to each other and in the case of a containerised vehicle to a predetermined boundary surface. Secondly, the vehicles must be constrained from moving away from their stowed configuration no matter to what handling loads they are subjected in transit.
In the case of shipping containers the first condition requires some type of spatial framework allowing for double tier or inclination of the vehicles to product maximum volume utilisation. The framework should weigh as little as possible for easy handling, and disassemble to a very small volume for empty return shipment. The framework should be rigid enough to maintain its dimensions within close limits and finally, because of its inherent rigidity, it should permit any transient forces to follow a load path to the base level of the container without the need of external help from the container walls or roof.
The second condition requires that the vehicles be connected to this space frame in such a way as to prevent their relative movement during transport, so necessitating either a direct rigid tie down via the vehicle chassis to the frame; or a tie down from some part of the wheels to the frame.
A framework on which motor vehicles can be supported within a shipping container is the subject of my U.S. Pat. No. 3,869,991, Mar. 11, 1975.
The present invention relates to a jack member two of which can be used together with the aforementioned framework to load and unload vehicles. To accomplish the loading the jack members are used to raise a vehicle to a position inclined to the horizontal within a container whereat they are supported by the framework. Conversely, to unload a container the jack members are used to lower the vehicles from their inclined, stowed position so that they can be driven out from the container.
A lifting jack which can be used to raise and lower a vehicle to and from a position inclined to the horizontal is disclosed in U.S. Pat. No. 3,780,987 (Craft et al) and No. 2,489,056.
Craft et al teaches a low profile lifting jack which is particularly useful for lifting vehicles having a small ground clearance such as forklift trucks. In use, this type of lifting jack normally is manually positioned beneath a vehicle which is to be raised and then operated to lift the vehicle. The jack member according to the present invention is intended for operation in a confined space and, in use, two such members are first located in accordance with the track of the vehicle which is to be raised whereafter the vehicle is driven onto the jack members. The vehicle automatically is positioned so that it can be lifted together with a part of its support framework. The framework is erected whilst the jack members hold the vehicle and when the framework is assembled to support that vehicle the jack members are removed.
The members are of adjustable length so that vehicles of different wheel base can be accommodated.
Stewart teaches a wheeled truck jack in which a lifting arm of the jack is adjustable in length. The purpose of this provision in the wheeled truck jack is to enable different lift heights to be obtained. In the jack member according to the present invention the provision of adjustability cannot effect the lift height of the jack member. The lift height remains constant is necessitated by the height of the framework which is to support a raised vehicle.
The invention provides a jack member for use in raising and lowering a vehicle to and from a position inclined to the horizontal, the jack member comprising an elongate approach ramp, an elongate lifting ramp, pivoting means extending transversely of the longitudinal axes of said ramps, whereby said ramps are connected together adjacent one of their ends, a pressure fluid ram pivotally connected to the ramps to rotate said lifting ramp with respect to said approach ramp from a first position to a second position, said lifting ramp including a surface defining a track along which track a vehicle wheel can run when the jack member is in its first position, support means provided at the said one end of said lifting ramp to receive means for cradling said vehicle wheel, and means allowing said wheel cradling to come into supporting engagement with said vehicle wheel when said pressure fluid ram has rotated said lifting ramp from said first position, in which said vehicle wheel runs along said ramps, into said second position in which the said one ends of said ramps are raised above their other ends.